Archival mounting corners are used for the non-destructive releasable retention of a primary sheet, such as a photograph or document, relative to a secondary sheet, such as a page of an album or book. The mounting corner includes a pocket for receiving a portion of the primary sheet and a base for securing to the secondary sheet. The mounting corner is affixed to the secondary sheet by an adhesive on the underside of the base. The adhesive covers the entire underside of the base. The adhesive may be a variety of types, including self-adhering, or wettable adhesives.
Although the use of an adhesive on the entire underside of the base provides for efficient manufacturing techniques, the presence of the adhesive proximal to the periphery of the mounting corner presents subsequent problems. Specifically, as the adhesive has an inherent flow rate, the adhesive gradually flows, or creeps, from between the mounting corner and the secondary sheet to contact the primary sheet. Any contact of the adhesive and the primary sheet may substantially damage the primary sheet.
The construction of the mounting corner also affects the integrity of the primary sheet. Mass manufacturing processes employ a vinyl or polyethylene coated polyester. Although these materials are readily heat bonded, they tend to degrade the primary sheet over extended periods of time. Polyester is a preferred material, as it provides a completely inert interface with the primary sheet. However, polyester does not exhibit broad tolerances in the preferred thermal bonding manufacturing techniques. Therefore, polyester is not employed for mass manufacturing mounting corners.
In addition, prior mounting corners are difficult to engage with the primary sheet. Many mounting corners require flexing or bending of the corner to allow engagement with the primary sheet.
Therefore, a need exists for an archival mounting corner formed of a completely inert material, such as uncoated polyester. A need also exists for a mounting corner which may be affixed to a secondary sheet such that inherent flow of the adhesive does not extend beyond the periphery of the corner. A further need exists for facilitating engagement of the mounting corner and the primary sheet.